Linda Hall Library

Find a library where document is available

This paper examines some of the commonly used design methods for overall stability based on factoring the passive resistance of the toe. These methods lead to widely differing levels of safety with respect to shear strength for a variety of conditions and sometimes give illogical results (e.g. A decreasing factor of safety with increasing wall penetration for uniform ground conditions). A revised definition of factor of safety with effect to passive failure is proposed. This revised definition is based on an analogy with bearing capacity theory and is shown to be consistent with the factor of safety as regards shear strength. The calculations take into account cohesive and frictional strength components, undrained conditions, surcharges and seepage pressures. A section deals with the application of the revised load factor to unpropped cantilever walls. The revised definition is shown to be logical and consistent for a wide range of conditions and overcomes the major difficulties that are inherent in current definitions. (TRRL)